Semiconductor components of the aforementioned type are described for example in U.S. Pat. No. 5,210,051, which discloses a semiconductor chip for a light-emitting diode. The semiconductor chip comprises an SiC substrate, on which an n-conducting and subsequently a p-conducting gallium nitride layer are applied. A radiation-generating pn junction is formed between the p-conducting layer and the n-conducting layer, and emits blue or violet light during operation. A contact metalization is applied on the p-conducting layer.
Such a semiconductor chip is generally provided with a protective layer. Said protective layer serves, in particular, for protecting the contact metalization from corrosion and mechanical damage, for example scratches. Moreover, electrical flashovers at the surface of the semiconductor body are suppressed. Such flashovers may primarily occur at the locations of the surface at which the pn junction is uncovered.
However, such a protective layer may greatly impair the electrical properties of the component. Thus, for forward-biased gallium-nitride-based light-emitting diodes, an increase in the forward voltage by more than 100% was ascertained in comparison with a component of the same type without a protective layer. This consequently led to a significant increase in the heat loss or the temperature of the component with a protective layer, and finally to the total failure thereof due to thermal overloading.